This invention relates to an actuation system, and more particularly to a flexible bellows actuation system which is capable of being folded without affecting its integrity or requiring complex dynamic seals and mechanical joints.
Actuation systems are required in many different types of apparatuses, in order to move elements of the apparatus which are more conveniently moved from a remote location than directly. One particular common aerospace application is the actuation of flight surfaces such as flaps or thruster controls. These surfaces are typically on an engine, wing, rotor, or stabilizer, and are not directly accessible to the aircraft pilot, but rather are actuated remotely from the cockpit by use of such an actuation system. Such an actuation system may be mechanical, electrical, or electro-mechanical.
Certain applications, particularly military in nature, sometimes require portions of the aircraft to fold, in order to decrease the overall dimensions of the aircraft for more compact storage. In such applications, the hinge line about which the craft is folded often intersects portions of one or more of the actuation systems, requiring that the actuation system be capable of being folded without affecting its integrity and reliability. Oftentimes, electronic or electromechanical actuators are not desirable because of the risks of jamming and electromagnetic interference (EMI). Weight, complexity, and the lack of available space at the designated break line often eliminates many mechanical candidates. For example, a standard hydraulic actuation system typically employs a ram and piston, both of which require dynamic seals. Such dynamic seals often result in leaks, which in turn cause many actuator failures.
What is needed, therefore, is an actuation system which is mechanical, simple, lightweight, and reliable, yet capable of being folded and unfolded repeatedly without loss of function or reliability.